High tolerance hole-plug for sheet metal

ABSTRACT

The invention pertains to a hole-plug for closing an access aperture in a sheet or plate-like support member. An externally flanged cup configured to be loosely received in the aperture, with the flange overlying the margin thereof, is clamped to the support member by a malleable metal spider positioned within and crosswise of the bottom of the cup. Initially the mid-portion of the spider is arched centrally outwardly from the cup bottom, and the legs of the spider are reversely arched with the tips disposed in registering slots formed in the cup wall. Flattening the arched mid-portion of the spider toward the bottom wall of the cup when the plug is placed in the hole to be closed causes the legs of the spider to expand radially outwardly and their tips to curl back into clamping engagement with the opposite surface of the support member engaged by the peripheral flange of the cup.

United States Patent Becker 1 June 27, 1972 [72] Inventor: Phillip D.Becker, Southbury, Conn.

[73] Assignee: Buell Industries, Incorporated, Waterbury,

Conn.

[22] Filed: April 14, 1971 [21] Appl. No.: 133,851

[52] US. Cl. ..220/25, 138/89, 220/55 Y [51 ..B65d 45/00 [58] Field ofSearch ..220/25, 24, 55 R, 55 Y, 55 A, 220/55 G, 55 H, 55 K, 55 Z, 55 P;138/89, 92

[56] References Cited UNITED STATES PATENTS 2,080,769 5/1937 Fitts..220/25 2,552,917 5/1951 Becker ..220/25 X 2,671,574 3/1954 Wolfe..220/24 A 2,735,5-71 2/1956 Lockwood ..220/25 2,735,572 2/1956 Getz..220/25 FOREIGN PATENTS OR APPLICATIONS 771,493 11/1967 Canada ..220/25Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-Thomas C. Culp,Jr. Attorney-Steward & Steward [5 7] ABSTRACT The invention pertains toa hole-plug for closing an access aperture in a sheet or plate-likesupport member. An externally flanged cup configured to be looselyreceived in the aperture, with the flange overlying the margin thereof,is clamped to the support member by a malleable metal spider positionedwithin and crosswise of the bottom of the cup. Initially the mid-portionof the spider is arched centrally outwardly from the cup bottom, and thelegs of the spider are reversely arched with the tips disposed inregistering slots formed in the cup wall. Flattening the archedmid-portion of the spider toward the bottom wall of the cup when theplug is placed in the hole to be closed causes the legs of the spider toexpand radially outwardly and their tips to curl back into clampingengagement with the opposite surface of the support member engaged bythe peripheral flange of the cup.

13 Claims, 8 Drawing Figures PATENTEDJum I972 SHEET 1 0F 3 INVENTOR.PHILLIP D. BECKER ATTORNEYS PATENTEDJUHN 1912 3. 672.532

' saw w 3 FIG. 8

HIGH TOLERANCE HOLE-PLUG FOR SHEET METAL The invention disclosed hereinis concerned with plugs adapted to be secured in and to close aperturesin a sheet or plate-like support member. The principal purpose is toprovide a closure for the aperture which effectively seals out dirt,water, fumes and the like, and is particularly useful in automotivestructures for sealing access openings fonned in body or chasis membersto facilitate manufacturing operations such as assembly of componentparts or drainage of excess rust-proofing composition. The plugs mayalso serve as a fastener device for securing two suitably aperturedsheets or plate members together in certain instances.

It is an object of the invention to provide improvement in the meansemployed for securing a hole-plug in an aperture of a support member,particularly in respect to adaptability of a hole-plug of given standardsize for slight variations in hole diameter or sheet material thicknessof the support member.

It is a known fact, for example in mass production such as automotivemanufacture, that wear of the tools used in punching access holes invarious sections or parts of an automotive body or chasis result in timein deviations from the standard or designed diameter of such holes. Itis also known that small deviations can occur in thickness of the sheetmetal stock, from one roll to another, from which body sections and thelike are formed, It is not always economically practical to maintain avery close tolerance on such aperture dimensions, and it is thereforecommon practice to rely instead on the plug to accomodate for suchout-of-tolerance deviations.

One of the most common types of hole-plugs utilized heretofore consistsof a central closure plate of a size and shape sufficient to overlap themargins of the aperture to be closed in a sheet support member, suchplate having on its under surface depending resilient spring fingerswhich serve frictionally to engage the edge of the aperture and hold thecover plate in place on the sheet support when the plug is pushed orhammered into the hole. Conventionally too, the resilient fingers of theplug are formed with some form of detent means adjacent their outerextremities which snap under the edge of the aperture when the plug isfully inserted, so as to reinforce the retaining forces acting tomaintain a plug in the hole. Unfortunately the adaptability of suchconventional hole-plugs to out-of-tolerance holes is narrowly limited,due to inherent limitations in the physical properties of the metal usedin forming the plug. Thus where other than strict design conditions arepresent, loss of such gripping action arises, particularly in the courseof time over the useful life of the article of manufacture such asautomobile body. This is of course aggravated by vibration and the plugwill drop out of the support member. The initial fit of the plug in thehole is therefore quite critical and it is conventional practice for themanufacturer to carry in stock a series of plugs for each nominal holediameter, where the plug diameters differ only slightly, in order toobtain a better initial fit in an out-of-tolerance hole. The sameconsiderations apply with respect to allowing for variations in sup portsheet thicknesses, all of which result in the need to stock amultiplicity of hold-plugs for a supposedly standard size hole. In largemass production operations, such multiplicity of plug sizes is not onlycostly, but adds to the complexity of selecting the proper plug for anygiven instance.

Attempts have, of course, been made to overcome this problem byproviding hole-plugs of designs capable of accommodatingout-of-tolerance variations, but it appears that in general suchprevious designs involve rather complex structural arrangements of thehole-plugs, with the result that they are expensive. It is accordingly afurther object of this invention to provide a hole-plug design ofgreater simplicity and lower cost of manufacture, without sacrifice inrespect to adaptability to accommodate for substantial out-of-tolerancedimensions in respect to either the nominal size of the hole in thesupport member or the thickness of such member, or both.

The invention is illustrated by the several embodiments shown in theaccompanying drawings in which:

FIG. I is an exploded view in perspective of a hole-plug of the presentinvention comprising a dished or cupped cover member and a cooperatingspider member for clamping the cover in position;

FIG. 2 is a top plan view of the assembled hole-plug ready for insertionin a hole;

FIG. 3 is a view, partly in cross-section, of a plug initiallypositioned in a hole to be sealed;

FIG. 4 is a cross-sectional view similar to FIG. 3 but showing the plugsecured in the aperture of the support member;

FIG. 5 is a split cross-sectional view of a modified form of hole-plug,showing initial and clamping positions of the plug;

FIG. 6 is a top plan view of an oval-shaped plug;

FIG. 7 is an exploded view in perspective of a further modifiedhole-plug; and

FIG. 8 is a top plan view of the plug of FIG. 7 in its initial assembledcondition.

A first form of the hole-plug incorporating the present invention isshown in FIGS. 1 through 4 of the accompanying drawings. The assembledhole-plug 10 in this embodiment consists of two members, the first beinga shallow cup or dished plate 12, and the other a complementary clampingmember or spider 14. Cup 12 is preferably formed of drawn sheet metal toprovide a circular cylindrical side wall 16 integrally connected to abottom wall 18 forming the closed end of the cup, and an integralexternally peripheral flange 20 at the open end of the cup. Bottom wall18 is pierced or slotted, as at 22, at circumferentially spaced pointsadjacent the juncture of bottom and side walls 18, 20, respectively. Thechordal portions of bottom wall 18 subtended between slots 22 and theside wall of the cup are pressed axially inwardly of the cup to formbridging elements overlying the tips of the spider legs received in theslots.

Clamp member 14 which cooperates with the cup 12 is preferably a sheetmetal stamping constituting a spider having a main central body portion26 from which integrally connected legs 28 radiate, there being foursuch legs in the embodiment here shown oriented to register with slots22 of cup 12. Legs 28 are bent along their longitudinal axes in respectto the body portion 26 of the spider to arch that body portion upwardlyaway from the plane defined by the tips or extremities of the legs. Legs28 are also reversely arched near their free ends to provide tipportions 30 which are received in the respective slots 22 of the cupmember in the assembled condition of the hole-plug 10, as seen in FIGS.2 and 3. Longitudinally inwardly to each tip portion 30, the side edgesof the legs are shouldered at 32 to form stops which, when engagedagainst opposite ends of the respective slots 22, prevent furtherextension beyond such shoulders of legs 28 relative to the slots.Preferably also the main body 26 of the spider 14 is domed upwardly, asseen at 34 in the drawings, to provide an impact resistant surface whenthe spider is hammered into clamping position.

The cylindrical or side wall 16 of cup 12 is configured to conform tothe shape of an aperture A in sheet support member S to be closed by thehole-plug 10, forming a relatively loose peripheral fit therein, as bestseen in FIGS. 3 and 4. And external flange 20 on cup 14 is likewiseconfigured to the general shape of the aperture, but of a widthsufficient to substantially overlap the margin M of the aperture A inthe sheet support member S.

Referring now to FIG. 4, plug 10 is secured in closing relation toaperture A of sheet supporting member S by hammering the main bodyportion 26 of spider l4 downwardly toward bottom wall 18 of the closingcup member 12. In so doing, the spider 14 is deformed from its initialupwardly arched position shown in dotted lines in FIG. 4 to asubstantially flat position adjacent the bottom wall 18 of cup I4, asshown in the solid line in FIG. 4. As spider 14 is flatened in thismanner, legs 28 are caused to expand radially outward through slots 22in the bottom wall of the cup, and by virtue of the reverse arch or bendof the tips portions 30 of the legs, they are forced upwardly intogripping engagement with the opposite face of sheet supporting member Sfrom that engaged by flange 20. Shoulders 32 on legs 28 limit the extentto which each leg can be forced outwardly through its respective slot22, thereby ensuring that all legs are uniformly extended and that allof them project into gripping engagement with the undersurface of thesheet support member S.

In the illustrations given in FIGS. 3 and 4, the difference in diameterof aperture A of member S and that of the cup portion of plug issomewhat exaggerated for purposes of clarity of illustration. However itwill be apparent that the design of hole plug provides substantialleeway for oversize of the aperture from a nominal standard diameter,and the gripping engagement for securing the plug in position is notaffected by such over-tolerance variation since the clamping action isnot conditioned upon making a frictional fit with the edge wall of theaperture as in conventional hole-plugs. By the same token, reasonablevariation in thickness of the support member S beyond a nominal standardlikewise does not adversely effect the clamping action of the plug,since such variation is readily taken up by the spring action of tips 30of spider 14 in engaging the undersurface of the support.

In the modified form of hole-plug shown in FIG. 5, the root portion 121of flange 120 is arched to provide a pocket in conjunction with sidewall 116 for the reception of agasketing or sealing compound. This ispreferably of the flowed-in type which adheres to the walls of thethus-formed pocket, as seen in the lefthand portion of the view in FIG.5. When this plug is inserted in an aperture A of a supporting member S,the gasketing material is caused by the clamping action to deform aboutand provide a substantially fluid-tight seal around the periphery of theplug. (See the righthand portion of FIG. 5). This arrangement has thefurther advantage that some gasketing material is caused to flow aboutthe intersection of legs 128 of the clamping spider with slots 122 ofcup 112, thereby furthering a completely water-tight arrangement.

The foregoing embodiments of the invention illustrated in FIGS. 1through 5 are all directed to plugs of circular configuration; but it isapparent that plugs of the invention can be adapted for use in closingapertures of non-circular form. For example, plug assemblies of square,rectangular or polyginal shape can be formed, or for example ofelliptical contour as shown in FIG. 6. Furthermore the embodimentillustrated in that figure employs two separate clamping spiders 214,each extending transversely of the minor axis of the plug in spacedrelation, although it will be apparent that a suitably formed one-piece,multi-legged spider similar to that illustrated in the foregoingexamples could also be employed The particular form of spiders 214 hereshown are further described in connection with the following additionalembodiment of the invention illustrated in FIG. 7 and 8.

Referring to FIG. 7, a circular hole-plug assembly 310 is again shownand comprises a shallow cup member 312 and cooperating two-legged spideror clamping member 314. Cup 312 is slotted at diametrically opposedlocations at the juncture of side and bottom walls 316, 318,respectively to provide a pair of leg-receiving apertures 322. Spider314 consists simply of a metal strap bent transversely of its length toform an intermediate arched body portion 326, from opposite sides ofwhich legs 328 extend downwardly, terminating in reversely arched tipportions 330. Legs 328 are shouldered at 332 to provide stops forengaging the ends of slots 322 to limit the extent to which legs 328 canbe forced outwardly through the slots of the cup member. In order tofacilitate the flattening of spider 314, a hole 315 is punched throughthe central body portion 326, weakening it transversely at the centerbend. In other respects this plug assembly is similar to those shown inthe foregoing illustrations, except that the chordally subtendedbridging portions adjacent slots 322 are omitted or at least minimizedto the extent that it is practical to do so in piercing the sheet metalof the cup to provide the slots. Such bridging portions are sometimeshelpful in securing a more water-tight fit between the cup and legmembers, and may have a beneficial effect in assisting the clampingaction of the spider legs. They are not however indispensible to thebroader aspects of the invention.

Other adaptations of the invention include the use of the hole-plug as afastener device for securing together two or more suitably aperturedsheet or plate members by bringing their apertures into registry andthen inserting a hole-plug and driving the spider legs into clampingposition. In such use it is obvious that the depth of the cup member mayhave to be increased to accommodate the greater support memberthickness.

The illustrated embodiments represent currently preferred specific formsof practicing the invention in the best known manner, but it will beobvious that various details of the design may be altered withoutdeparting from the inventive concept characterizing the invention. Thatis, a hole plug comprising a cup member which serves not only to formthe closing cover for an aperture in a support member, but also as ananvil against which a clamping spider is deformed to cause its leg toproject radially through slots in the cup member and into engagementwith the opposite surface of the supporting member from that engaged byan external flange or periphery of the cup. The clamping action of thehole-plug thus produced is accordingly independent of the exact diameterof the aperture, within the limits of the width of the externalperipheral flange, and also independent of the thickness of theapertured supporting member, again within limits of the cup depth.

What is claimed is:

1. A hole-plug for closing an aperture in a sheet support member,comprising a sheet metal cup having a generally cylindrical side wall ofa size and shape to be loosely received in the hole to be plugged, abottom wall integrally joined to said side wall to form the closed endof said cup, and an external peripheral flange integrally joined to andextending radially outward from said side wall at the open end of saidcup, said flange being of a width and contour to substantially overliethe margin of the hole to be plugged, and said cup having at least two,generally diametrically opposed, slots piercing the cup adjacent thejuncture of said bottom and side walls;

a clamp member disposed in said cup for securing it in holepluggingposition in an aperture of a support member, said clamp membercomprising a relatively stiff but malleable sheet metal spider having amain body portion and integrally connected leg portions radiating fromsaid body portion and corresponding in number and circumferentialorientation with said slots in said cup member so as to registertherewith, said leg portions having their tips received in respectiveslots of said cups and making a close sliding fit therewith, said legsbeing arched to dispose said main body portion in elevated position insaid cup member;

said clamp member being adapted and arranged to cause said leg portionsto expand radially through said cup slots when the central arcuate bodyportion of said clamp member is flatened inwardly toward the bottom wallof said cup, whereby said tips are caused to overlap and grip the marginof the hole in said support member on the face thereof opposite thatengaged by said annular cup flange.

2. A hole-plug as defined in claim 1, where the edges of the legs ofsaid clamp member are formed to provide shoulders adjacent their freeends to engage opposite ends of said slots in said cup member and limitthe radial expansion of each leg through its respective slot.

3. A hole-plug as defined in claim 2, wherein the free ends of said legsare reversely arched longitudinally outwardly of said shoulders.

4. A hole-plug as defined in claim 2, wherein said slots are formed winsaid bottom wall chordally thereof, and the subtended arcuate portionsof the bottom wall are bridged inwardly to overlie the free ends of saidlegs.

5. A hole-plug as defined in claim 2, wherein said slots are formed inthe side wall of said cup member to receive the free ends of said legs.

6. A hole-plug as defined in claim 2, wherein said clamp member isformed with two legs and said cup member is provided with diametricallyopposed slots to receive said legs.

7. A hole-plug as defined in claim 2, wherein said clamping member isformed with four legs and said cup member is provided with two pairs ofslots, the slots in each pair being diametrically opposed to receivesaid legs.

8. A hole-plug as defined in claim 1, wherein said cup member is formedwith two pairs of slots, the slots in each pair being diametricallyopposed, and two clamp members, each such member having oppositelyextending legs received in a respective pair of slots.

9. A hole-plug as defined in claim 8, wherein said cup member is ofnon-circular configuration.

10. A hole-plug as defined in claim 9, wherein said cup member is ofelliptical configuration.

11. A hole-plug as defined in claim 1, wherein the center of said mainbody portion of said spider is formed with a dome.

12. A hole-plug as defined in claim 1, wherein the center of said spiderbody portion is bent transversely of the legs, and an aperture is formedin the bend.

13. A hole-plug as defined in claim 1, wherein a sealing compound isadhered to the under surface of the external peripheral flange of saidcut adjacent the root of said flange.

1. A hole-plug for closing an aperture in a sheet support member,comprising a sheet metal cup having a generally cylindrical side wall ofa size and shape to be loosely received in the hole to be plugged, abottom wall integrally joined to said side wall to form the closed endof said cup, and an external peripheral flange integrally joined to andextending radially outward from said side wall at the open end of saidcup, said flange being of a width and contour to substantially overliethe margin of the hole to be plugged, and said cup having at least two,generally diametrically opposed, slots piercing the cup adjacent thejuncture of said bottom and side walls; a clamp member disposed in saidcup for securing it in holeplugging position in an aperture of a supportmember, said clamp member comprising a relatively stiff but malleablesheet metal spider having a main body portion and integrally connectedleg portions radiating from said body portion and corresponding innumber and circumferential orientation with said slots in said cupmember so as to register therewith, said leg portions having their tipsreceived in respective slots of said cups and making a close sliding fittherewith, said legs being arched to dispose said main body portion inelevated position in said cup member; said clamp member being adaptedand arranged to cause said leg portions to expand radially through saidcup slots when the central arcuate body portion of said clamp member isflatened inwardly toward the bottom wall of said cup, whereby said tipsare caused to overlap and grip the margin of the hole in said supportmember on the face thereof opposite that engaged by said annular cupflange.
 2. A hole-plug as defined in claim 1, where the edges of thelegs of said clamp member are formed to provide shoulders adjacent theirfree ends to engage opposite ends of said slots in said cup member andlimit the radial expansion of each leg through its respective slot.
 3. Ahole-plug as defined in claim 2, wherein the free ends of said legs arereversely arched longitudinally outwardly of said shoulders.
 4. Ahole-plug as defined in claim 2, wherein said slots are formed win saidbottom wall chordally thereof, and the subtended arcuate portions of thebottom wall are bridged inwardly to overlie the free ends of said legs.5. A hole-plug as defined in claim 2, wherein said slots are formed inthe side wall of said cup member to receive the free ends of said legs.6. A hole-plug as defined in claim 2, wherein said clamp member isformed with two legs and said cup member is provided with diametricallyopposed slots to receive said legs.
 7. A hole-plug as defined in claim2, wherein said clamping member is formed with four legs and said cupmember is provided with two pairs of slots, the slots in each pair beingdiametrically opposed to receive said legs.
 8. A hole-plug as defined inclaim 1, wherein said cup member is formed with two pairs of slots, theslots in each pair being diametrically opposed, and two clamp members,each such member having oppositely extending legs received in arespective pair of slots.
 9. A hole-plug as defined in claim 8, whereinsaid cup member is of non-circular configuration.
 10. A hole-plug asdefined in claim 9, wherein said cup member is of ellipticalconfiguration.
 11. A hole-plug as defined in claim 1, wherein the centerof said main body portion of said spider is formed with a dome.
 12. Ahole-plug as defined in claim 1, wherein the center of said spider bodyportion is bent transversely of the legs, and an aperture is formed inthe bend.
 13. A hole-plug as defined in claim 1, wherein a sealingcompound is adhered to the under surface of the external peripheralflange of said cut adjacent the root of said flange.